The first parameter 'irq' is never used by
kstat_incr_irqs_this_cpu(). Remove it.
Signed-off-by: NJiang Liu <jiang.liu@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/1433391238-19471-16-git-send-email-jiang.liu@linux.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This will allow to use the dummy IRQ handler no_action() from drivers
compiled as module. Drivers which use ARM FIQ interrupts can use this
to request the interrupt via the normal request_irq() mechanism w/o
having to copy the dummy handler to their own code.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Link: http://lkml.kernel.org/r/1395476431-16070-1-git-send-email-shc_work@mail.ruSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

In course of the sdhci/sdio discussion with Russell about killing the
sdio kthread hackery we discovered the need to be able to wake an
interrupt thread from software.

The rationale for this is, that sdio hardware can lack proper
interrupt support for certain features. So the driver needs to poll
the status registers, but at the same time it needs to be woken up by
an hardware interrupt.

To be able to get rid of the home brewn kthread construct of sdio we
need a way to wake an irq thread independent of an actual hardware
interrupt.

Provide an irq_wake_thread() function which wakes up the thread which
is associated to a given dev_id. This allows sdio to invoke the irq
thread from the hardware irq handler via the IRQ_WAKE_THREAD return
value and provides a possibility to wake it via a timer for the
polling scenarios. That allows to simplify the sdio logic
significantly.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Chris Ball <chris@printf.net>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140215003823.772565780@linutronix.de

We've been moving away from add_interrupt_randomness() for various
reasons: it's too expensive to do on every interrupt, and flooding the
CPU with interrupts could theoretically cause bogus floods of entropy
from a somewhat externally controllable source.

This solves both problems by limiting the actual randomness addition
to just once a second or after 64 interrupts, whicever comes first.
During that time, the interrupt cycle data is buffered up in a per-cpu
pool.  Also, we make sure the the nonblocking pool used by urandom is
initialized before we start feeding the normal input pool.  This
assures that /dev/urandom is returning unpredictable data as soon as
possible.

(Based on an original patch by Linus, but significantly modified by
tytso.)
Tested-by: NEric Wustrow <ewust@umich.edu>
Reported-by: NEric Wustrow <ewust@umich.edu>
Reported-by: NNadia Heninger <nadiah@cs.ucsd.edu>
Reported-by: NZakir Durumeric <zakir@umich.edu>
Reported-by: J. Alex Halderman <jhalderm@umich.edu>.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

exit_irq_thread() clears IRQTF_RUNTHREAD flag and drops the thread's bit in
desc->threads_oneshot then. The bit must not be set again in between and it
does not, since irq_wake_thread() sees PF_EXITING flag first and returns.

Due to above the order or checking PF_EXITING and IRQTF_RUNTHREAD flags in
irq_wake_thread() is important. This change just makes it more visible in the
source code.
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120321162212.GO24806@dhcp-26-207.brq.redhat.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The current implementation does not always flush the threaded handler
when disabling the irq. In case the irq handler was called, but the
threaded handler hasn't started running yet, the interrupt will be
flagged as pending, and the handler will not run. This implementation
has some issues:

First, if the interrupt is a wake source and flagged as pending, the
system will not be able to suspend.

Second, when quickly disabling and re-enabling the irq, the threaded
handler might continue to run after the irq is re-enabled without the
irq handler being called first. This might be an unexpected behavior.

In addition, it might be counter-intuitive that the threaded handler
will not be called even though the irq handler was called and returned
IRQ_WAKE_THREAD.

Fix this by always waiting for the threaded handler to complete in
synchronize_irq().

[ tglx: Massaged comments, added WARN_ONs and the missing
  	IRQTF_RUNTHREAD check in exit_irq_thread() ]
Signed-off-by: NIdo Yariv <ido@wizery.com>
Link: http://lkml.kernel.org/r/1322843052-7166-1-git-send-email-ido@wizery.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Currently IRQTF_DIED flag is set when a IRQ thread handler calls do_exit()
But also PF_EXITING per process flag gets set when a thread exits. This
fix eliminates the duplicate by using PF_EXITING flag.

Also, there is a race condition in exit_irq_thread(). In case a thread's
bit is cleared in desc->threads_oneshot (and the IRQ line gets unmasked),
but before IRQTF_DIED flag is set, a new interrupt might come in and set
just cleared bit again, this time forever. This fix throws IRQTF_DIED flag
away, eliminating the race as a result.

[ tglx: Test THREAD_EXITING first as suggested by Oleg ]
Reported-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120309135958.GD2114@dhcp-26-207.brq.redhat.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

The detection of spurios interrupts is currently limited to first level
handler. In force-threaded mode we never notice if the threaded irq does
not feel responsible.
This patch catches the return value of the threaded handler and forwards
it to the spurious detector. If the primary handler returns only
IRQ_WAKE_THREAD then the spourious detector ignores it because it gets
called again from the threaded handler.

[ tglx: Report the erroneous return value early and bail out ]
Signed-off-by: NSebastian Andrzej Siewior <sebastian@breakpoint.cc>
Link: http://lkml.kernel.org/r/1306824972-27067-2-git-send-email-sebastian@breakpoint.ccSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Last user gone.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We really need these flags for some of the interrupt chips. Move it
from internal state to irq_data and provide proper accessors.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: David Daney <ddaney@caviumnetworks.com>

For level type interrupts we need to track how many threads are on
flight to avoid useless interrupt storms when not all thread handlers
have finished yet. Keep track of the woken threads and only unmask
when there are no more threads in flight.

Yes, I'm lazy and using a bitfield. But not only because I'm lazy, the
main reason is that it's way simpler than using a refcount. A refcount
based solution would need to keep track of various things like
crashing the irq thread, spurious interrupts coming in,
disables/enables, free_irq() and some more. The bitfield keeps the
tracking simple and makes things just work. It's also nicely confined
to the thread code pathes and does not require additional checks all
over the place.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110223234956.388095876@linutronix.de>

The WARN_ON_ONCE in handle_percpu_event() which emits a warning when
an action handler returns with interrupts enabled is not really
useful. It does not reveal the interrupt number and handler function
which caused it. Make it WARN_ONCE() and add the information.
Reported-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

note_interrupt wants to be called with the combined result of all
handlers called, not with the last one. If it's a shared interrupt
then the last handler might return IRQ_NONE often enough to trigger
the spurious dectector which turns off a perfectly fine working
interrupt line. Bug was introduced in commit 1277a532(genirq: Simplify
handle_irq_event()).

Yes, I really messed up there. First the variable ret should not have
been named differently to avoid similarity with retval. Second it
should have been declared in the do {} loop.

Rename it to res and move it into the do {} loop and vanish under a
huge brown paperbag.
Reported-bisected-tested-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Force the usage of wrappers by another nasty CPP substitution.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Keep status in sync until all users are fixed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We need to maintain the flag for now in both fields status and istate.
Add a CONFIG_GENERIC_HARDIRQS_NO_COMPAT switch to allow testing w/o
the status one. Wrap the access to status IRQ_INPROGRESS in a inline
which can be turned of with CONFIG_GENERIC_HARDIRQS_NO_COMPAT along
with the define.

There is no reason that anything outside of core looks at this. That
needs some modifications, but we'll get there.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Now that all core users are converted one layer can go.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Core code replacement for the ugly camel case. It contains all the
code which is shared in all handlers.

     clear status flags
     set INPROGRESS flag
     unlock
     call action chain
     note_interrupt
     lock
     clr INPROGRESS flag
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We run all handlers with interrupts disabled and expect them not to
enable them. Warn when we catch one who does.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

All architectures are finally converted. Remove the cruft.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Michal Simek <monstr@monstr.eu>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>

kernel/irq/handle.c has become a dumpground for random code in random
order. Split out the irq descriptor management and the dummy irq_chip
implementation into separate files. Cleanup the include maze while at
it.

No code change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

This option covers now the old chip functions and the irq_desc data
fields which are moving to struct irq_data. More stuff will follow.

Pretty handy for testing a conversion, whether something broke or not.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Wrap the old chip function startup() until the migration is complete and
the old chip functions are removed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.635152961@linutronix.de>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Wrap the old chip functions disable() and shutdown() until the
migration is complete and the old chip functions are removed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.532070631@linutronix.de>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Wrap the old chip function enable() until the migration is complete and
the old chip functions are removed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.437159182@linutronix.de>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Wrap the old chip function ack() until the migration is complete and
the old chip functions are removed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.142624725@linutronix.de>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Wrap the old chip function unmask() until the migration is complete
and the old chip functions are removed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121842.043608928@linutronix.de>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Wrap the old chip function mask() until the migration is complete and
the old chip functions are removed.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.940355859@linutronix.de>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

The compat functions go away when the core code is converted.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Convert all references in the core code to orq, chip, handler_data,
chip_data, msi_desc, affinity to irq_data.*
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Low level chip functions need access to irq_desc->handler_data,
irq_desc->chip_data and irq_desc->msi_desc. We hand down the irq
number to the low level functions, so they need to lookup irq_desc.
With sparse irq this means a radix tree lookup.

We could hand down irq_desc itself, but low level chip functions have
no need to fiddle with it directly and we want to restrict access to
irq_desc further.

Preparatory patch for new chip functions.

Note, that the ugly anon union/struct is there to avoid a full tree
wide clean up for now. This is not going to last 3 years like __do_IRQ()
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100927121841.645542300@linutronix.de>
Reviewed-by: NH. Peter Anvin <hpa@zytor.com>
Reviewed-by: NIngo Molnar <mingo@elte.hu>

Running interrupt handlers with interrupts enabled can cause stack
overflows. That has been observed with multiqueue NICs delivering all
their interrupts to a single core. We might band aid that somehow by
checking the interrupt stacks, but the real safe fix is to run the irq
handlers with interrupts disabled.

Drivers for whacky hardware still can reenable them in the handler
itself, if the need arises. (They do already due to lockdep)

The risk of doing this is rather low:

 - lockdep already enforces this
 - CONFIG_NOHZ has shaken out the drivers which relied on jiffies updates
 - time keeping is not longer sensitive to the timer interrupt being delayed
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@osdl.org>
LKML-Reference: <20100326000405.758579387@linutronix.de>

Use radix_tree irq_desc_tree instead of irq_desc_ptrs.

-v2: according to Eric and cyrill to use radix_tree_lookup_slot and
     radix_tree_replace_slot
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-32-git-send-email-yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Add replace_irq_desc() instead of poking at the array directly.

-v2: remove unneeded boundary check in replace_irq_desc
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-31-git-send-email-yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

mem_init is moved early already.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-29-git-send-email-yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Convert locks which cannot be sleeping locks in preempt-rt to
raw_spinlocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NIngo Molnar <mingo@elte.hu>

After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>

when there is no ram on node 0.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
LKML-Reference: <4A95C32D.5040605@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Ingo had

[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: at mm/bootmem.c:537 alloc_arch_preferred_bootmem+0x2b/0x71()
[    0.000000] Hardware name: System Product Name
[    0.000000] Modules linked in:
[    0.000000] Pid: 0, comm: swapper Tainted: G        W  2.6.30-tip-03087-g0bb2618-dirty #52506
[    0.000000] Call Trace:
[    0.000000]  [<81032588>] warn_slowpath_common+0x60/0x90
[    0.000000]  [<810325c5>] warn_slowpath_null+0xd/0x10
[    0.000000]  [<819d1bc0>] alloc_arch_preferred_bootmem+0x2b/0x71
[    0.000000]  [<819d1c31>] ___alloc_bootmem_nopanic+0x2b/0x9a
[    0.000000]  [<81050a0a>] ? lock_release+0xac/0xb2
[    0.000000]  [<819d1d4c>] ___alloc_bootmem+0xe/0x2d
[    0.000000]  [<819d1e9f>] __alloc_bootmem+0xa/0xc
[    0.000000]  [<819d7c63>] alloc_bootmem_cpumask_var+0x21/0x26
[    0.000000]  [<819d0cc8>] early_irq_init+0x15/0x10d
[    0.000000]  [<819bb75a>] start_kernel+0x167/0x326
[    0.000000]  [<819bb06b>] __init_begin+0x6b/0x70
[    0.000000] ---[ end trace 4eaa2a86a8e2da23 ]---
[    0.000000] NR_IRQS:2304 nr_irqs:424
[    0.000000] CPU 0 irqstacks, hard=821e6000 soft=821e7000

we need to update init_irq_default_affinity
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>